Category 4 on the SSHWS will be broadened by one mph at each end of the range, yielding a new range of 130-156 mph. This will also result in a minor modification of the Category 3 and 5 wind speed thresholds. The SSHWS will change as follows:
From:
Category 3: 111-130 mph (96-113 kt, 178-209 km/h)
Category 4: 131-155 mph (114-135 kt, 210-249 km/h)
Category 5: 156 mph or higher (136 kt or higher, 250 km/h or higher)
To:
Category 3: 111-129 mph (96-112 kt, 178-208 km/h)
Category 4: 130-156 mph (113-136 kt, 209-251 km/h)
Category 5: 157 mph or higher (137 kt or higher, 252 km/h or higher)
There will be no change to the wind speeds currently assigned to Categories 1 and 2.
With this change, a 115-kt Category 4 hurricane will have its intensity properly converted to mph and rounded to the nearest 5 mph (130 mph) and remain within the Category 4 mph range.
Important note: Since intensities are assigned using 5-kt increments, neither storms in the historical record nor any future storms will have their SSHWS category changed as a result of this modification to the scale.